MPLAB XC16: Mixing C and Assembly

I am attempting to mix some C and assembly language and I am having a bear of a time. I am experienced with C, somewhat with assembly, but I haven't used them on the same project before.

At the moment, I am attempting to compile the simplest possible project, which is a Q1.15 fixed-point multiplication. I don't actually care about the code output, I just needed something to compile so that I could build off of it.